PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. I. PHOTOCHEMISTRY MODEL AND BENCHMARK CASES
We present a comprehensive photochemistry model for exploration of the chemical composition of terrestrial exoplanet atmospheres. The photochemistry model is designed from the ground up to have the…
Phosphine gas in the cloud decks of Venus
- J. Greaves, A. Richards, J. Hoge
- Physics, Environmental ScienceNature Astronomy
- 14 September 2020
Measurements of trace gases in planetary atmospheres help us explore chemical conditions different to those on Earth. Our nearest neighbour, Venus, has cloud decks that are temperate but hyperacidic.…
Many chemistries could be used to build living systems.
- W. Bains
- ChemistryAstrobiology
- 3 September 2004
It is argued that it is the nature of the liquid in which life evolves that defines the most appropriate chemistry, and Fluids other than water could be abundant on a cosmic scale and could be an environment in which non-terrestrial biochemistry could evolve.
Exoplanet Biosignatures: A Framework for Their Assessment
- D. Catling, J. Krissansen‐Totton, S. Domagal‐Goldman
- Geology, PhysicsAstrobiology
- 18 May 2017
This work presents a framework in which it is proposed that resulting posterior Bayesian probabilities of life's existence map to five confidence levels, ranging from “very likely” (90–100%) to “ very unlikely” (<10%) inhabited.
BIOSIGNATURE GASES IN H2-DOMINATED ATMOSPHERES ON ROCKY EXOPLANETS
Super-Earth exoplanets are being discovered with increasing frequency and some will be able to retain stable H2-dominated atmospheres. We study biosignature gases on exoplanets with thin H2…
A BIOMASS-BASED MODEL TO ESTIMATE THE PLAUSIBILITY OF EXOPLANET BIOSIGNATURE GASES
Biosignature gas detection is one of the ultimate future goals for exoplanet atmosphere studies. We have created a framework for linking biosignature gas detectability to biomass estimates, including…
An astrophysical view of Earth-based metabolic biosignature gases.
- S. Seager, M. Schrenk, W. Bains
- Physics, GeologyAstrobiology
- 23 January 2012
Key points of Earth-based microbial metabolism that are useful to the astrophysical search for biosignature gases on exoplanets are reviewed, including a list of primary and secondary metabolism gas byproducts.
PHOTOCHEMISTRY IN TERRESTRIAL EXOPLANET ATMOSPHERES. II. H2S AND SO2 PHOTOCHEMISTRY IN ANOXIC ATMOSPHERES
Sulfur gases are common components in the volcanic and biological emission on Earth, and are expected to be important input gases for atmospheres on terrestrial exoplanets. We study the atmospheric…
Toward a List of Molecules as Potential Biosignature Gases for the Search for Life on Exoplanets and Applications to Terrestrial Biochemistry.
- S. Seager, W. Bains, J. Petkowski
- Physics, GeologyAstrobiology
- 1 April 2016
A new approach to the subject of biosignature gases is presented by systematically constructing lists of volatile molecules in different categories, and it is shown that about one-fourth of CNOPSH molecules are known to be produced by life on Earth.
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